Intelligent track and navigation for sensor carrier

ABSTRACT

Systems and techniques for a sensor carrier, and intelligent track infrastructure for the navigation and operation of the sensor carrier are described. The sensor carrier is an autonomous robot navigating a track. The carrier holds cameras and other sensors to receive horticultural images and telemetry for plants in a grow operation. The carrier reads embedded signals in the track including Radio Frequency Identifier (RFID) tags, embedded positioning magnets, and drilled hole patterns for a beam breaking system to determine navigation and operation. For tracks placed at sharp angles, a transfer station with wall guards to prevent the carrier from falling enable safe transfers from different track segments. Additional features include an emergency stop (e-stop) switch and power management for autonomous sensor carriers.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/155,849 filed Oct. 9, 2018, entitled “Intelligent Track andNavigation for Sensor Carrier” which claims priority to provisionalpatent application Ser. No. 62/570,615 filed on Oct. 10, 2017, entitled“Intelligent Track and Navigation for Sensor Carrier”. Theabove-identified applications are hereby incorporated by reference.

BACKGROUND

Horticultural operations are experiencing a boom with AgriculturalTechnology (“AgroTech”). In AgroTech, plants and other aspects of growoperations are surrounded by sensors which provide telemetry which areaggregated in a central station for further analysis. Analysis of thereceived telemetry provides a farmer or grower feedback as to the stateof his or her crop. In this way, problems with crops can be detected andaddressed quickly, thereby optimizing yields and lowering growoperational costs.

Presently, there is not a cost-effective way to instrument growoperations with sensors. Grow operations are increasing in complexityand scale. Accordingly, AgroTech operations are expected to match thisgrowth while controlling cost of instrumentation.

BRIEF DESCRIPTION OF THE DRAWINGS

The Detailed Description is set forth with reference to the accompanyingfigures.

FIG. 1a and 1b illustrates a top-level context diagrams for anintelligent track and navigation for a sensor carrier.

FIG. 2 is a block diagram of an example architecture for an intelligenttrack and navigation for a sensor carrier.

FIG. 3 is a block diagram for is a block diagram of an intelligent trackand navigation for a sensor carrier.

FIG. 4 is an illustration of an inverted orientation for a sensorcarrier on an intelligent track.

FIG. 5 is a flowchart for processing positioning feedback for a sensorcarrier on an intelligent track.

FIG. 6 is a flowchart for processing positioning feedback for a sensorcarrier on an intelligent track.

FIG. 7 is a flowchart for performing power management for a sensorcarrier on an intelligent track.

FIG. 8 is a diagram of a transfer station for an intelligent track.

FIG. 9 is a flowchart for the operation of a transfer station on anintelligent track.

DETAILED DESCRIPTION Context of an Intelligent Track and Navigation fora Sensor Carrier

AgroTech makes use of a sophisticated set of high performance sensors.There are high fidelity cameras which are able to capture optical imagesin sufficient detail for making use of computer object recognitiontechniques. There are also other sensors to monitor environmentalvariables such as water levels, pH, humidity and temperature. The volumeof data collected by high fidelity cameras and sensors is quite largeand is sufficient to provide a statistically significant data set formachine learning. Such sensors, transducers, cameras, and other inputscan be expensive. Accordingly, it may not be cost effective to install aset of sensors for each plant.

The approach of the present disclosure is to install one or moreautonomous robotic carriers that house one or more high-fidelity camerasand optionally additional sensors. These robots collect telemetry andother inputs from a single plant or location of plants in a growoperation, and then rove on a track to move to then next plant orlocation of plants. In this way, each plant or location of plants issubjected to high-fidelity imaging and sensing, without a grower havingthe cost of high-fidelity imaging and sensing for each plant.

FIG. 1a is a top-level context diagram 100 for an intelligent track andnavigation for sensor carriers. In the present disclosure, an autonomousrobotic carrier (sometimes called a shuttle or more generically arobot), 102 contains a power system, computing processor, memory, aplurality of sensors 104 and cameras 106 to take telemetry, mediacapture, or other inputs of plants in a greenhouse. A discussion of theinternals of a carrier is provided with respect to FIG. 3 below.

A carrier 102 is networked via a wireless communications network 108such as a Wi-Fi access point 110a or a cellular network femtocell 110 b.On the wireless communications network 108 is a gateway server 111. Thegateway server, orchestrates and executes image downloading from acarrier 112. Exemplary algorithms are to use round robin or networkpriority schemes, or a combination of the two. The gateway server 111also acts as a local storage waypoint for images as well as data priorto pushing to a cloud-based location. Via the gateway server 111, aremote controller 112 is used to control the carriers, such as thecarrier 112, over the wireless communications network 108.

The carriers run on a fixed arrangement of tracks 114 affixed to theceiling 116 of a greenhouse or other surrounding structure of ahorticultural operation. The carrier 102 is inverted, i.e. it runsunderneath the track 114, in order to take pictures of the plantsunderneath 118. The inverted configuration of the carrier 102 isdescribed in further detail with respect to FIG. 4 below.

Since the carrier 102 services multiple plants 118, the carrier 102 isconfigured to precisely locate itself at least with respect to itsmounting track 114. FIG. 1b is a top view of a track 114 showingpotential positions 120 of a carrier 102 with respect to the track 114.The bolded circle indicates a specific current location 122 in agreenhouse of the carrier 102 with respect to the track. A descriptionof positioning feedback from the track 114 enabling the carrier 102 todetermine its location and to navigate and to effect positioningfeedback is described in further detail with respect to FIG. 5 below.

From an operational perspective, industrial systems generally haveemergency cutoffs. Since the carriers 102 are autonomous, theintelligent track and navigation for sensor carrier infrastructurefeatures an emergency cutoff to stop carrier operations, even though thecarriers 102 are autonomous. This emergency cutoff is described infurther detail with respect to FIG. 6 below.

The autonomous nature of the carriers 102 is a recurring theme. Becausethe carriers 102 are autonomous, there is neither a central controllerto recall carriers for recharging, nor is there a separate power linealong the track 114. Power management techniques such as systemhibernation and other improved power management techniques are describedin further detail with respect to FIG. 7 below.

Finally, since carriers 102 are expensive, extra care is taken to ensurethe carriers 102 do not fall from the track 114. One point of risk iswhere a carrier 102 transfers from one track 114 to another, such aswhen making a turn. A transfer station 124 with a mechanical wall guardis disclosed. The transfer station 124 minimizes the risk that a carrierfalls from the track during a turn, transferring of tracks 114 or at theend of a track 114. The transfer station 124 is described in greaterdetail with respect to FIG. 8.

Exemplary Architecture for an Intelligent Track and Navigation for aSensor Carrier

Prior to describing the carrier and the tracks, the general computingenvironment is described with respect to FIG. 2.

Functionality for the carriers 102 and for the remote controllers 112 ofthe carriers are generally hosted on a computing device 202. Exemplarycomputing devices 202 for the carriers 102 include without limitationsmall scale computers such as a Raspberry Pi, embedded devices, andrepurposed smartphones. Exemplary computing devices 202 for the remotecontrollers 112 without limitation include personal computers, laptopcomputers, netbooks, tablet computers and smartphones.

The computing devices 202 are to be networked. The carriers themselveshave on board computers as described in further detail with respect toFIG. 3.

The computing device 202 has a processor 204, a memory 206. Theprocessor may be a central processing unit, and/or a dedicatedcontroller such as a microcontroller. The computing device for the mayfurther include an input/output (I/O) interface 208, and/or a networkinterface 210. The I/O interface 208 may be any controller card, such asa universal asynchronous receiver/transmitter (UART) used in conjunctionwith a standard I/O interface protocol such as RS-232 and/or UniversalSerial Bus (USB). In the case of a carrier, a computing device may usethe I/O interface 208 for both sensors for navigation, and media capturedevices such as a digital camera.

The network interface 210 works in concert with the I/O interface 208and may be a network interface card supporting Wi-Fi and/or any numberof other physical and/or datalink protocols. Alternatively, the networkinterface 210 may be in the form of a cellular network interface.

Memory 206 is any computer-readable media which may store severalsoftware components including an operating system 212 and softwarecomponents such a control software, media capture/telemetry softwareand/or other applications 214. In general, a software component is a setof computer-executable instructions stored together as a discrete whole.Examples of software components include binary executables such asstatic libraries, dynamically linked libraries, and executable programs.Other examples of software components include interpreted executablesthat are executed on a runtime such as servlets, applets, p-Codebinaries, and Java binaries. Software components may run in kernel modeand/or user mode.

Computer-readable media includes, at least, two types ofcomputer-readable media, namely computer storage media andcommunications media. Computer storage media includes volatile andnon-volatile, removable and non-removable media implemented in anymethod or technology for storage of information such as computerreadable instructions, data structures, program modules, or other data.Computer storage media includes, but is not limited to, RAM, ROM,EEPROM, flash memory or other memory technology, CD-ROM, digitalversatile disks (DVD) or other optical storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,or any other non-transmission medium that can be used to storeinformation for access by a computing device. In contrast, communicationmedia may embody computer readable instructions, data structures,program modules, or other data in a modulated data signal, such as acarrier wave, or other transmission mechanisms. As defined herein,computer storage media does not include communication media.

A server 216 is any computing device that may participate in a network.The network may be, without limitation, a local area network (“LAN”), avirtual private network (“VPN”), a cellular network, or the Internet.The server 216 has analogous components as to the computing devices 202.Specifically, it will include a processor 218, a memory 220, aninput/output interface 222 and a network interface 224. In the memorywill be an operating system 226 and application software 228. The roleof the server 216 is to aggregate media and telemetry from carriers andto perform analytics and image processing either locally or via theinternet and/or cloud 230. Collected/aggregated data may be stored onserver-side data store 232.

A service on the cloud 230 may provide the services of a server 216. Aserver, may either be a physical dedicated server, or may be a virtualmachine. In the latter case, the cloud 230 may represent a plurality ofdisaggregated servers which provide virtual application server 234functionality and virtual storage/database 226 functionality. Thedisaggregated servers are physical computer servers, which may have aprocessor, a memory, an I/O interface and/or a network interface. Thefeatures and variations of the processor, the memory, the I/O interfaceand the network interface are substantially analogous to those describedfor server 216. Differences may be where the disaggregated servers areoptimized for throughput and/or for disaggregation.

Cloud 230 services may be made accessible via an integrated cloudinfrastructure 238. Cloud infrastructure 238 not only provides access tocloud services, but also to billing services and other monetizationservices. Cloud infrastructure 238 may provide additional serviceabstractions such as Platform as a Service (“PAAS”), Infrastructure as aService (“IAAS”), and Software as a Service (“SAAS”).

Exemplary Carrier Internals and System Block Diagram

The discussion around FIG. 2 describes the computing environment for thecarrier 102 and intelligent track 114 in general. FIG. 3 is a blockdiagram of the intelligent track and navigation for sensor carrierinfrastructure 300.

Infrastructure 300 has four major subsystems: the carrier subsystem 302,the imaging subsystem 304, the track subsystem 306 (for track 114), andthe transfer station subsystem 308 (for transfer station 124). Each ofthese subsystems and their communications are described below.

The carrier subsystem 302 performs the functions directed toward movingand navigating the carrier 102. The brains are a processor, such as anIntel x86 based central processing unit (CPU) on an on-board computer.In some embodiments, a supplementary microcontroller such as an STM32may be used to translate CPU instructions into mechanical instructionsto the mechanical portions of the carrier 102. If a microcontroller isused, then the CPU and the microcontroller communicate via a UART.

The on-board computer is networked via Wi-Fi to a Wi-Fi access point inthe greenhouse. Alternatively, the network may be a cellular networkcentered by a femtocell. An emergency stop is configured to directlycommunicate with the carrier 102 over the network. In this way, theemergency stop may stop a specific carrier 102, or alternativelymultiple carriers 102, immediately. The emergency stop is described infurther detail with respect to FIG. 6.

The carrier subsystem 302 includes sensors to determine direction,orientation and stability. For example, the carrier subsystem 302includes both linear and rotational sensors.

Power is stored in a battery managed by a power supply. Power isreceived externally from a base station from a power receiver mediatedby a charging circuit prior to charging the battery. The power from thebattery powers not only the processing of the carrier 102,communications, and the motors of the carrier 102, but also the imagingsubsystem 304 which is physically mounted on the carrier 102 and whoseorientation is directed by a powered multi-axis gimbal.

The imaging subsystem 304 includes 2D still cameras and may optionallybe configured with video cameras. In some cases, the cameras aremulti-spectral and may use non-visual spectra such as infrared. A camerareceives control commands, such as commands to capture images. Thecamera also receives focusing commands from the on-board computer whichalso controls a programmable focus lens for the camera.

The imaging subsystem 304 includes a 3D camera, which is a stereo visioncamera enabled to communicate depth information. The 3D camera is usedby the carrier to inform an obstruction sensor. When the obstructionsensor senses that the carrier 102 is unable to move, the 3D camera cantransmit visual information indicating the cause of the obstruction.

Turning back to the carrier subsystem 302, the carrier 102 has a drivermotor controlled by the on-board computer which in turn drives a wheelagainst track 114. The carrier stays on the track 114 via guidebearings.

Navigation of the carrier 102 makes use of three sensors. A rotaryencoder measures the revolutions by a guide wheel and calculates thedistance that the carrier 102. The carrier 102 then makes use of RadioFrequency Identifier (RFID) tags on the track 114 or positioning magnetson the track 114 and uses an RFID reader or a Hall Effect sensorrespectively to detect its position.

The track subsystem 306 is comprised of a plurality of track segmentsconnected with track couplers. The connected track segments constitutetrack 114 and are connected to the facility structure, such as a ceiling116 of a greenhouse, via mounting brackets. As previously stated, thetrack subsystem contains RFID tags and positioning magnets to indicatepositions. Positioning feedback is described in further detail withrespect to FIG. 5.

The track subsystem 306 also makes use of a coding system of holes inthe track segments to indicate position, usually at the end of the track114. The carrier includes a beam transmitter and a beam receiver withthe track in between. While the carrier 102 is passing over track 114portions without holes, the beam is broken, indicating that the carrier102 may move without concern of falling off the end of a track 114. Whenthe carrier 102 passes a portion of track 114 with a hole, the beam thenshines through and is received by the beam receiver indicating to thecarrier that it should stop or slow down to avoid moving off the end ofthe track 114. The beam breaking technique is described in furtherdetail with respect to FIG. 5.

Note that some track segments may simply end. Other track segments maybe connected to one another via a transfer station 124. Accordingly, wenow turn to the transfer station subsystem 308. The subsystem 308includes a coordination of the transfer station 124 and the carrier 102.Both the carrier 102 and the transfer station 124 communicate with eachother over the communications network. The communications network may beWi-Fi or alternatively may be cellular. The transfer station 124 issituated on portions of the track 114 with holes acting as flagsindicating position with respect to the transfer station. The transferstation 124 has a base mount with a beam break sensor. The discussionwith respect to FIG. 9 describes the operation of the transfer station124 in more detail.

Inverted Carrier Configuration

FIG. 4 is an illustration of the carrier 102 mounted on the track 114.Note that carriers 102 are mounted inverted (i.e. riding underneath thetrack). The carriers 102 are overhead track-mounted self-propelledrobots that use an interconnected track system with transfer stations toenable track switching. A user controls and directs a carrier 102 in aparticular direction to a specified location using a set of firmwarecommands containing distance parameters and/or preconfigured locationidentifiers. The passive indicators in the track, such as RFID tags andpositional magnets may be used to place the carrier 102 on the track,and to receive commands to capture images, capture telemetry, uploaddata or alternatively to perform maintenance actions such asdiagnostics.

Tracking Positional Feedback for a Carrier

An imaging subsystem 304, comprising one or more cameras, rides on acarrier 102. The carrier 102 has positional awareness via several formsof wireless way-finding techniques as follows.

An initial position may be determined with a rolling rotary encoder. Arotary encoder counts ticks and frequency of ticks of a drag wheelcorresponding to the revolutions of the drag wheel rolling along thetrack. This tick count data is then converted to velocity and distancetraveled information. In this way, the carrier 102 is aware of itsvelocity and distance traveled and may combine this information with itsnavigational path along the track 114 to infer its position.

However, a rotary encoder can only provide position with respect to aknown initial position. Additionally, the rotary encoder may sufferslippage error and over time and distance, its readings may becomeunreliable. To obtain absolute position, the carrier 102 reads eitherRFID tags using an RFID tag sensor or magnets via Hall Effect sensors todetermine its absolute position. The RFID tag sensor and Hall Effectsensors on the carrier 102 sense the presence of passive RFID tags andmagnets respectively, that are located periodically along the track.This provides gross positional awareness of which track the carrier 102is on, and which direction the carrier 102 is facing, and provides itsabsolute position.

Note that the carrier 102 autonomous. Accordingly, the carrier 102 isconfigured to have redundant inputs to ensure that broken sensors may bedetected and the operation of the carrier 102 does not become faulty.The carrier 102 makes use of optical beam-break sensing to coordinatewith the other sensors. Specifically, the optical beam-break sensorsdetect patterns of drilled holes in the track. These drilled holepatterns may encode a count of track segments traversed, and denote thepresence of special track elements, such as a charging station, an RFIDtrack, or an approaching end-of-track or location within a transferstation 124.

FIG. 5 is a flowchart 500 of the coordination of these various sensors.In block 502, a carrier 102 starts operation by moving down a track 114.In block 504, the carrier 102 senses either a positional magnet or anRFID tag indicating its initial position. In block 506, it startsmeasuring ticks on the rotary encoder to determine velocity and itsdistance from its initial position.

In block 508, the beam breaker sensor reads a pattern of holes drilledin the track 114 indicating that a track with an RFID tag or magnet iscoming up. The beam breaker sensor may be configured to measure lightintensity. Where there are more holes or larger holes, more lightpasses. The amount of light may be coded to describe upcoming or presenttrack conditions.

Alternatively, the holes may be spaced at different intervals. Thepattern of passing light turning on and off based on hole spacing mayalso be coded to describe upcoming or present track conditions. Finally,holes may be positioned into different patterns for a single scan. Thepositional patterns of the holes may be coded to describe upcoming orpresent track conditions.

The carrier 102 then starts a timer to determine the time betweenreceiving the beam break signal and receiving the RFID tag or magnetsignal.

In block 510, if the RFID tag or magnet is detected, the timer isstopped and the carrier 102 resets its initial position to that of theRFID tag or magnet.

In block 512, if the RFID tag or magnet is not detected before the timertimes out to a predetermined time, then the carrier 102 signals the basestation and the user may opt to engage an e-Stop button to stop thecarrier 102. The e-Stop button is described with respect to FIG. 6.

Emergency Cutoff Switch for Multiple Track Mounted Carriers

Because a carrier 102 is not tethered to any power source and does notoperate in the direct vicinity of users, a typical emergency stop button(e-stop button) is not optimal. Accordingly, the intelligent track andnavigation for sensor carriers infrastructure includes a wireless e-stopbutton. A wireless e-stop button is battery powered and only draws powerwhen its “mushroom top” button is pressed. Once pressed, the button willstay pressed until disengaged by the user. FIG. 6 is a flowchart 600 ofthe operation of the e-stop button.

Consider the scenario where a user either receives an indication from acarrier 102 or can visually see, that a carrier 102 is amiss. Forexample, the user may note that a track 114 is out, or that a carrier102 is in danger of running off a track 114. Alternatively, telemetryfrom the carrier 102 may appear to be incorrect, and the user may wishto stop operations for debugging.

In block 602, the e-stop button senses that the button has been pressed.The button then mechanically locks into place. In block 604, in responseto being pressed, the e-stop button sends via wireless network acontinuous kill signal. This kill signal will continue until the e-stopbutton is disengaged.

Note that each carrier 102 is outfitted with a radio receiver that runsdirectly off the battery independent of all other systems. In block 606,the carrier 102 receives the kill signal. Responsive to receiving thekill signal, the carrier opens a relay that disconnects power to therest of the carrier 102.

In block 608, the e-stop button is manually disengaged, and accordinglystops transmitting the kill signal. At this point, every carrier 102 inrange of the e-stop button when it was pressed will cease alloperations. In block 610, the power relay on each carrier 102 can onlybe closed again by manually cycling power with its on-board powerswitch. In this way, in an emergency situation all carriers 102 withinrange of the kill signal will stop and not restart without interventionby the user.

Power Management for Intelligent Track and Navigation for SensorCarriers

The carrier 102 is designed to maximize the potential duty cycle ofrunning versus charging. It is advantageous to find a way to minimizepower use at times when the device is charging and performing no otheroperational duties.

One method for the carrier 102 to reduce power consumption is to allowthe power circuit to control the power mains on the carrier, includingthe power to the on-board computer. During long charge cycles (e.g.overnight or other down times), the on-board computer may issue acommand to the power circuit to initiate a system hibernation cycle.However, the carrier 102 is autonomous and so is configured to reawakenitself from the hibernation cycle without user intervention. Since theon-board computer is typically the device that issues commands to thepower circuit, this technique represents a complete handoff of systemcontrol from the on-board computer to the power circuit.

FIG. 7 is a flowchart 700 of the hibernation and re-awaken cycle of thecarrier 102. In block 702, the on-board computer determines that thecarrier 102 is not instructed to perform any operations presently andwithin a predetermined amount of time. In block 704, responsive to thedetermination, the carrier 102 returns to a base station for recharging,couples its recharging interface with the base station charger andinitiates charging.

In block 706, the on-board computer initiates hibernation by sendinginstructions to the power circuit to disable at least one of the mainpower circuits, if not all. The instructions include a condition toreawaken the power circuits after hibernation. Example conditionsinclude a predetermined amount of time to pass prior to reawakening andan indication that a predetermined amount of charge is present in thebattery.

In block 708, the power circuit, rather than the on-board computer,detects that the conditions to reawaken have occurred, and re-enablesthe main power circuits.

As a result, during hibernation and recharge, the on-board computer willbe completely unpowered thereby saving power and expediting recharge.

Wall and Gate Transfer Station for Intelligent Track and Navigation forSensor Carrier

As described above, some track segments are connected at sharp anglessuch that the carrier 102 is unable to turn. For example, a tracksegment may intersect with another track segment at a 90-degree angle,such that the carrier 102 cannot execute a turn. In these situations,the track 114 may be configured to have a wall and gate transfer station124 at the junction of the track segments. The transfer station 124receives a carrier 102 from a first track segment, and mechanicallyrotates the carrier 102 to orient with a second track segment. Uponcompletion of the rotation, the carrier 102 continues onto the secondtrack.

The transfer station 124 in effect is a rotating section of track.Accordingly, it is desirable to have a mechanical backup to prevent acarrier 102 from running off the end of the track or otherwise fallingoff The transfer station 124 features a rotating table surrounded bystationary wall sections that prevents the carrier 102 from leaving theprimary track or leaving the transfer station until the transfer trackis properly aligned with the primary track.

FIG. 8 is an illustration 800 of an exemplary transfer station 124. Thetransfer station 124 includes a first track slot 802, a rotating table804, and a slot for a second track 810, and a wall guard 812. FIG. 9 isa flowchart 900 of the operation of the transfer station 124. In block902, the carrier 102 is continuing along a track 114 and passes apattern of holes allowing beam from a beam transmitter on the carrier102 to be received by a beam receiver on the carrier. The track 114 hadintervened between the transmitter and receiver blocking the beam. Uponpassing the pattern of holes, the beam receiver interprets the patternand informs the carrier 102 that it is approaching a transfer station.If a predetermined amount of time passes without encountering a transferstation, the carrier 102 transmits an error signal.

In block 904, the carrier 102 enters the transfer station 124, 800, anda beam break sensor in the transfer station 124, 800 senses the carrier102 and tells the carrier 102 to stop.

In block 906, responsive to the carrier 102 stopping, a switchcontroller (the controller for the transfer station 124) starts a motorto rotate the rotating table 804 as to reorient the carrier 102 from thefirst track segment to the second track segment. If the rotation appliessufficient force to the carrier 102 to risk a drop, or if the carrier102 erroneously attempts to move, the wall guards 812 will block thecarrier 102.

In block 908, once the rotation is complete, the transfer station 124signals the carrier 102 that it may move again and proceed to the secondtrack 810.

CONCLUSION

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

What is claimed is:
 1. A method of a sensor carrier mounted on a trackto navigate the track, comprising: initiating at a carrier a firstoperation by proceeding on a track; sensing at the carrier a passivetrack signal on the track corresponding to a first track position;responsive to sensing a position indicator, measuring ticks on a rotaryencoder to determine velocity and its distance from the first trackposition; sensing at a second sensor, an indicator of an upcomingcondition and initiating at the carrier a timer; if a subsequent passivetrack signal is detected, stopping the timer and resetting an initialposition of the carrier to that subsequent passive track signal, and ifa subsequent passive track signal is not detected before a predeterminedamount of time is measured by the timer, then transmitting at thecarrier an error signal.
 2. The method of claim 1, wherein the indicatorof an upcoming condition sensed by the second sensor indicates any oneof the following: an upcoming track segment with an RFID tag; anupcoming track segment with a positional magnet; and an end of thetrack.
 3. The method of claim 1, wherein the passive signal on the trackis an embedded positional magnet sufficient to trigger a Hall Effect. 4.The method of claim 1, wherein the passive signal on the track is anRadio Frequency Identifier (RFID) tag.
 5. The method of claim 4, whereinthe RFID tag trigger commands to perform any one of the following:capture images; collect telemetry; transmit data including images andtelemetry; and perform maintenance.
 6. The method of claim 1, whereinthe indicator of an upcoming condition sensed by the second sensor is apattern of drilled holes in the track, sufficient to pass light andtrigger a beam receiver.
 7. The method of claim 6, wherein the patternof drilled holes in the track are encoded to any one of the following:amount of light passing through the hole or pattern of holes; a spacingof holes along the track; and a positional pattern of holes.
 8. Themethod of claim 6, wherein the pattern of holes indicates an upcomingtransfer station.
 9. A method for a transfer station to coordinate asensor carrier track transfer, comprising: receiving from a carrier viaan interpretation of a pattern of holes, that a transfer station isabout to be entered; transmitting a signal that the carrier has enteredthe transfer station and is situated on a track mounted on a rotatingtable, and to stop movement; responsive to the carrier stopping,initiating at the transfer station a switch controller to rotate therotating table to reorient the carrier 102 from a first track segment toa second track segment; and determining that the rotating table asoriented the carrier to the second track, and responsive to thedetermination, signaling the carrier to proceed on the second track. 10.A transfer station apparatus to transfer a sensor carrier between tracksegments, comprising: a transfer station base plate, orientedhorizontally; a rotating table comprised of a flat disk with a fixedradius, the flat disk parallel to the base plate and situated under thebase plate, coupled via an axle positioned through a vertical hole inthe base plate to a switch motor; a table track segment with a length ofa diameter of the rotating table, and situated under the rotating tablepassing through the center of the rotating table; a first track segmentcoupler underneath the transfer station base plate situated radially outfrom the rotating table and placed with one end at the radius of thebase plate, as to connecting a first track segment to the table tracksegment; a second track segment coupler underneath the transfer stationbase plate situated radially out from the rotating table and placed withone end at the radius of the base plate, as to connecting a second tracksegment to the table track segment, the second track segment not beingparallel to the first track segment; and wall guards placed underneaththe base plate at a perimeter of the transfer station, with a heightsufficient to stop a sensor carrier on the track from falling of theend, wherein the wall guards have gaps sufficiently wide to allow thesensor carrier to pass from the first track segment to the second tracksegment.
 11. The apparatus of claim 10, wherein the wall guards and thetrack segment couplers are removable and may be placed into respectiveslots at the perimeter of the rotating table.
 12. The apparatus of claim11, wherein the transfer station further comprises a wirelesscommunications interface configured to communicate with a sensor carrierover a wireless communications network.
 13. The apparatus of claim 12,wherein the wireless communications interface is via any one of thefollowing: Wi-Fi wireless communications; and cellular wirelesscommunications.
 14. The apparatus of claim 12, further comprising anemergency stop (e-stop) switch communicatively coupled to the transferstation and to the sensor carrier via the wireless communicationsnetwork, wherein upon the e-stop switch being engaged, the sensorcarrier is configured to stop operation.
 15. The apparatus of claim 13,wherein the sensor carrier is configured to stop operation via a relayswitch to a power supply, such that restart of the sensor carrier is viaa manual cycling of the relay switch.
 16. The apparatus of claim 12,comprising a sensor that a sensor carrier is in the rotating table ofthe transfer station, wherein the wireless communications interface isconfigured to notify the sensor carrier to stop.
 17. The apparatus ofclaim 16, wherein the sensor that a sensor carrier is in the rotatingtable is a beam breaking sensor.
 18. The apparatus of claim 12,comprising a sensor that the rotating table is oriented to a secondtrack segment, wherein the wireless communications interface isconfigured to notify the sensor carrier to start.
 19. A power managementapparatus for a sensor carrier, the sensor carrier configured to operateautonomously, comprising: an on-board computer; a battery; a receivingpower interface; a power circuit coupled to the battery and to theon-board computer; and a power main to the on-board computer therebypowering the on-board computer; wherein the power circuit is configuredto receive a charging instruction from the on-board computer to couplethe receiving power interface to a charger, and to shut off the powermain to the on-board computer and to restore the power main upon apredetermined condition being satisfied.
 20. The apparatus of claim 19,wherein the predetermined conditions are any one of the following: thebattery is charged to a predetermined amount; and a predetermined amountof time has passed.